1. Field of the Invention
The present invention relates to a seat belt system for a vehicle, and more particularly, to a seat belt system for a front seat of a vehicle having a double-door structure.
2. Description of the Related Art
Conventionally, in a vehicle of a passenger car or like, a three-point seat belt restraint configuration for a front seat includes a retractor for retracting a webbing, a shoulder anchor for slidably supporting the webbing above and outward of a passenger, and a lap anchor for fixedly supporting the webbing below and outward of the passenger, which are disposed on a center pillar of a vehicle body. However, in a vehicle having a double door structure with no center pillar, the retractor, the shoulder anchor, and the lap anchor of a seat belt system for a front seat are disposed in the rear door in consideration of convenience for the rear passengers during ingress or in egress, as disclosed in Japanese Patent Publication No. 2001-105864.
When the lap anchor is disposed in the center pillar of the body, the location of the lap anchor (or an anchor point) can be positioned below the lower edge of the door. However, when the lap anchor is disposed in the rear door as described above, the lap anchor is inevitably positioned above the lower edge of the door so as not to impede the opening and closing motion of the rear door, which results in a higher location of the anchor point. This causes no problem for the passenger protection in a vehicle which provides a relatively higher hip point for the passenger, but may cause a problem in a vehicle which provides a relatively lower hip point for the passenger. That is, the higher anchor point may possibly be inadequate for the seat belt to protect the passenger, because the webbing restraints the passenger at a relatively higher location thereon.
In view of the above problem, an object of the present invention is to optimize the passenger protection performance of a seat belt system for a passenger in a front seat without impairing the convenience for the rear passengers during ingress or egress, particularly in a vehicle adopting a double-door structure with no center pillar and also providing lower hip point restraint for the passenger.
In accomplishing these and other objects of the present invention, there is provided a seat belt system for a vehicle for restraining an occupant in a first seat mounted in a passenger compartment of the vehicle, the vehicle including an opening formed on at least one side of a vehicular body. The seat belt system includes a belt webbing having a first and second end. A retractor is disposed at a door of the vehicle for retracting the first end of the belt webbing. A lap-anchor device is disposed at the door of the vehicle for fixedly supporting the belt webbing below and outward of the first seat. The lap-anchor device includes an anchor bracket and a moving device. The anchor bracket is connected with the second end of the belt webbing. The anchor bracket includes an engaging part which communicates with an engageable partion provided at the vehicular body below the opening. The anchor bracket is also movable between a first position above the lower edge of the door where the anchor bracket does not impede the opening and closing motion of the door and a second position below the lower edge of the opening where the engaging portion engages the engaged portion when the door is closed. The moving device moves the anchor bracket between the first position and the second position.
Accordingly, the moving device moves the anchor bracket in the vertical direction between the first position and the second position. When the door is open, the anchor bracket is moved to the first position, so as not to impede the opening and closing motion of the door. On the other hand, when the door is closed, the anchor bracket is moved downwardly to engage the engageable part, so that the second end of the belt webbing is fixed below the lower edge of the opening via the anchor bracket, thereby providing the optimized passenger protection performance of the seat belt system. In addition, when the engaging portion engages the engageable part, the door and the body can share load transmitted from the belt webbing via the lap-anchor device and the engaged portion, which can prevent the deformation or damage to the door and the body to ensure the passenger restraint performance of the seat belt system.
These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment relative to the accompanied drawings, in which: